Keppel receives award for rig design: Head of deep-water technology division, Aziz Amirali Merchant and team receives award from the Institution of Engineers Singapore for the Semi-submersible Drilling Tender (SSDT).
Rigs going green
As oil and gas operators venture into deeper waters to feed the global hunger for energy, a greater challenge exists to balance cost control with environmental concerns.
Environmentalists often blame the noise from seismic acquisition and drilling operations for the beaching of whales and other disruptions to marine life.
No less problematic is the decommissioning and disposal of a growing number of offshore production facilities at the end of their useful lives. When not properly carried out, the partial or complete removal of platforms can cause safety and environmental hazards to both humans and marine species.
These issues get more complicated in the remote deep-water oil and gas fields, where bigger production structures tend to be deployed and now share the habitats of larger marine species.
Industry players have developed new technology in attempt to resolve these issues, although, as yet, no one approach can offer a complete solution.
The semi-submersible drilling tender (SSDT) rig is one such innovation promising to reduce noise pollution and environmental footprint of oil and gas operations, according to Aziz Amirali Merchant, an industry veteran with more than 18 years of offshore marine experience.
SSDT carries a derrick and drilling package that can be shared across multiple offshore platforms, helping reduce a unit’s size and weight.
Merchant said oil and gas operators would save up to 40% from the construction of a smaller four-point as compared to a 16-point jacket.
At least $200 million could also be shaved from investment in derrick and drilling package for large deep-water production units like the tension leg or spar platforms, Merchant said.
Sharing equipment across production facilities is also expected to reduce the scale and complexity of decommissioning required on oil and gas projects.
Merchant heads up the deep-water technology division of Singapore-based rig and offshore marine vessel builder, Keppel. The rig builder is one half of the team behind the only deep-water semi-submersible tender drilling unit that is "operationally field proven", Merchant said.
Keppel’s SSDT rig design features an eight-point mooring system. The feature provides as further 75% savings on power consumption over other dynamically positioned semi-submersible rigs, Merchant said.
It also cuts sonic waves generated by a DP system, he added although the rig is unlikely to eliminate all white noise from drilling activities.
Despite the advantages highlighted by Merchant, the SSDT rig design is more suited to drill in a benign environment.
More work is also required to tailor the rig for the harsh-environment of the North Sea and the hurricane-prone US Gulf of Mexico, he said.
Keppel has delivered five SSDTs since 1994. All five have previously operated or are mostly working in both shallow and deep waters off Southeast Asia and West Africa.
Two other rigs under construction are due for completion later this year and in 2011.
One of the two rigs being built may be considered for Petrobras P-61 development, according to a source.
PetroVietnam’s drilling arm, PV Drilling, has also released a tender earlier this year for the construction of a unit similar to the 2006-built West Berani delivered from KeppelFels.
The last SSDT delivered from Keppel was built at a contract value of $160 million.
Merchant sees a potential demand for two to three such rigs each year worldwide.
That number, though encouraging, is a far cry from the 11 jack-up and four semi-submersible orders Keppel received in 2006 and to a certain extent, reflects the limitations of a SSDT.
SSDTs are designed primarily to support production drilling from platforms while jack-ups and semisubs can be used to drill both exploration and development wells.
The use of SSDTs in production drilling is also restricted by the design of platforms and well slots, according to an analyst.
One rig operator said jack-ups are better suited for drilling from a wellhead platform as compared to an SSDT unit.
Notwithstanding its limitations, the SSDT still offers distinct advantages in supporting drilling from TLPs and spars, the rig operator said. TLPs and spars are usually used to develop discoveries in water depths greater than 1000 feet.
Cost and benefits aside, more also needs to be done to promote an understanding of the SSDT technology.
Industry players require more education on the benefits of such a rig design, Merchant said.
The learning curve is steep indeed in the oil and industry, when it comes to new technology or environmental issues.